[OSM-talk] gpx format problem?

[Frank O'Dwyer]

SteveC wrote:
> * @ 13/05/06 12:15:09 PM fod at opencycleroute.org wrote:
>   
>> The problem seems to be that if the tracklog is saved under a filename 
>> on the device itself, the timestamps are discarded. If I retrieve the 
>> active log using mapsource, the timestamps are there. Pretty annoying! 
>> This is a garmin device (gpsmap 60csx).
>>     
>
> Nice unit (60csx).
>
> Mikel told me that it also compresses the traces when you save them on
> to a file on it from the mail tracklog so it's best to avoid that.
>   
Do you mean it drops points? For this particular trace it didn't seem to 
(but it's fairly short). Just the stamps seem to be missing.
>> Next question is are the timestamps actually used for anything? I could 
>> put in dummy timestamps if not.
>>     
>
> The idea is that they can be used to work out speed and other useful
> information.
>   
Trust me nobody's going to get any useful speed information from a trace 
of me tootling home on my brompton :-)

Seems to me like there are the following options:
1) I always get the trace from the active log (this is a problem if I 
want to do multiple traces before I get to my computer, which I do - 
although maybe I can save waypoints to help me remember where each trace 
starts and ends in the active log)
2) I put together some XSL or similar that shoves in dummy timestamps 
every 1 sec (however this will make it look like I did the journey by 
pushbike at an average speed of 65mph! - and there won't be anything in 
the data to flag that the timestamps are made up)
3) I put in obviously false timestamps like 1970 or something, which 
software that wants to process timestamps can filter out
4) Get OSM to accept GPXes which have no timestamp info (which maybe 
breaks something, I don't know)

Cheers,
Frank